media: tw9910: fix failure handling in tw9910_power_on()

If gpiod_get_optional() fails in tw9910_power_on(), clk is left undisabled.

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/i2c/tw9910.c

@@ -610,6 +610,11 @@ static int tw9910_power_on(struct tw9910_priv *priv)
 					     GPIOD_OUT_LOW);
 	if (IS_ERR(priv->rstb_gpio)) {
 		dev_info(&client->dev, "Unable to get GPIO \"rstb\"");
+		clk_disable_unprepare(priv->clk);
+		if (priv->pdn_gpio) {
+			gpiod_set_value(priv->pdn_gpio, 1);
+			usleep_range(500, 1000);
+		}
 		return PTR_ERR(priv->rstb_gpio);
 	}